1. Field of the Invention
This invention is in the field of lint handling devices for automatic washing machines and makes use of serrated edges which upon rotation of the pump impeller serve to abrade and shred lint tending to build up around the impeller shaft seal and thereby prevent an accumulation of lint pieces which could be harmful to the proper operation of the pump.
2. Description of the Prior Art
In Platt U.S. Pat. No. 3,653,807 issued Apr. 4, 1972 and assigned to the assignee of the present application, there is described a method and apparatus for treating lint in an automatic washing machine wherein a lint bearing liquid is withdrawn from the washing tub, the lint is shredded in the wash liquid, the lint is filtered from the shredded lint bearing wash liquid, the filtrate is pumped back into the tub, the filter is back flushed at predetermined intervals, the lint in the liquid resulting from the back flushing is shredded and ultimately discharged from the machine.
It is known to combine macerating or grinding means into an automatic dish washer as shown in U.S. Pat. Nos. 3,310,243 and 3,370,598. There are also examples in the prior art wherein pumps are provided with cutting means or the like driven on a common shaft with the pump impeller, as for example in U.S. Pat. Nos. 1,192,575; 2,042,641; and 2,306,298. A related disclosure is found in U.S. Pat. No. 2,496,359 which shows a disintegrator or cutting device for insertion in sewer lines. U.S. Pat. No. 3,060,483 describes a cutting arrangement for a textile suction cleaner which employs a cutter to sever yarn, tape or lint to prevent those materials from clogging a machine blower. U.S. Pat. No. 2,143,693 is directed to a protective device for a ship's propeller. This device includes a protective sleeve which carries saw teeth on a cutting edge formed on the outer end portion of the protective sleeve facing the propeller shaft. The purpose of the device is to prevent foreign objects such as a rope becoming enmeshed in the propeller or propeller shaft and bearing assembly which might cause damage to those parts.